The crop harvesting header assembly of an agricultural combine is conventionally mounted on the front end of the chassis in the combine. The header assembly extends forwardly of the front wheels of the combine and cuts a wide swath of the crop as the combine is driven through the standing crop in a field. The header assembly is connected to the combine body on the chassis by a cut crop feeder assembly. The feeder assembly carries the cut crop upwardly and rearwardly into the combine's threshing assembly.
The header assembly is conventionally cantilevered from the front end of the combine chassis on the feeder assembly, which permits it to move up and down and tilt relative to the combine's longitudinal axis so that a cutter bar extending transversely across the front of the header assembly is free to follow the contour of the field. The cutter bar and, accordingly, the header assembly are supported for travel over the terrain at a uniform height on a series of runners which depend from the trailing edge of the cutter bar. A crop cutter blade is mounted in the cutter bar for reciprocating cutting movement longitudinally of the bar.
Depending upon the crop being harvested, a header assembly may include a series of crop lifter arms mounted on a cutter bar guard and extending forwardly from it. The crop lifter arms are spaced twelve to eighteen inches from each other along the cutter bar guard, transversely of the header assembly. With a twenty-four foot wide header assembly harvesting a vine-type crop such as soy beans, for example, it is conventional to have as many as twenty crop lifter arms mounted on the cutter bar guard in relatively closely spaced relationship.
In a conventional set-up, the closely spaced crop lifter arms are mounted on the cutter bar guard, forwardly of, and below, the guard point. The lifter arms are mounted on the cutter bar guard for limited vertical pivoting movement.
Each lifting arm has a crop lifting surface extending the length of its upper edge. The angle of the lifting surface on each lifter arm relative to the ground is steep along virtually its entire length, e.g., an angle of about 45.degree. is typical.
The aforedescribed conventional construction and set-up of crop lifter arms in a header assembly for an agricultural combine has numerous shortcomings, however. It results in the crop being cut off relatively high and at inconsistent heights. It results in foreign material easily entering the cutting blade area. It creates a substantial amount of stress in the cutter bar guard and related structure.